Knish is Jewish soul food, a soft pillow of baked or fried dough that is usually stuffed with onions and mashed potatoes. This comfort food was brough to New York City's Lower East Manhattan and Brooklyn around 1900, when Jewish immigrants from Eastern Europe first started selling it from their street carts.
Round knishes are baked, while square knishes are typically fried. Today, these flavorful snacks are found throughout New York's shops and delis, and there isn't a bar mitzvah party that doesn't include knishes. As the dish gained popularity throughout the years, various unusual fillings started to be added to it, such as broccoli, cheddar cheese, corned beef, and sauerkraut.